Glass run guides for slidable vehicle windows

Abstract: A glass run guide for retaining and smoothly guiding a slidable vehicle window includes a molded polymeric strip (20) having a substantially U-shaped transverse cross section including a base (24), an inboard leg (26), having a projecting lip portion (30) which engages an interior surface of a slidable vehicle window (12), and an outboard leg (28) having a projecting lip portion (32), which engages an exterior surface of the slidable vehicle window (12). The glass run guide is formed of a fiber reinforced polymer having sufficient -strength and rigidity to counter forces exerted by the sliding vehicle window (12) and is mounted below the vehicle beltline to prevent undesirable movements of the window. The surfaces of the lip portions (30, 32) which contact the surfaces of the slidable vehicle window are low friction, non-abrasive surfaces which facilitate smooth movement of the window as it is raised or lowered.

Description: This specification relates generally to glass run guide members disposed within an automotive vehicle door having a slidable window, and which serve to smoothly guide the window as it is being lowered into or raised from the well of the door. Automotive vehicle doors are almost invariably provided with a sliding window which can be raised to a position sealingly closing a window opening and which can be lowered to a position wherein the window is stored in a cavity within the vehicle door. The periphery of the window opening in a vehicle door is generally provided with a plurality of polymeric sealing elements having resilient elastomeric characteristics to allow for smooth movement of the window and to ensure sealing engagement between the window and that portion of the door frame defining the window opening, even after thousands of cycles between the open and closed positions over many years of service. The sealing elements surrounding the window opening generally include a header and pillar or side elements which typically have a substantially U-shaped portion into which the edges of the window are received, and a pair of opposing inner and outer beltline sealing elements which are attached to the door frame along the lower edge of the window opening. The header, pillar and beltline sealing elements are generally attached to a pinchweld flange or U-shaped channel formed by the sheet metal defining the doorframe, with the door frame serving as a reinforcement for the sealing elements to stabilize or counter forces exerted by the window along its edges as it is being raised or lowered. Below the beltline, within the door cavity or well, the window is typically guided by a pair of spaced parallel rails or glass runs. The belowbelt glass runs generally comprise an elastic U-shaped member of, for example, rubber which does not serve a sealing function, but instead provides a nonabrasive, low-friction guide liner which promotes smooth movement of the window as it is being raised or lowered. Typically, the edges of the door frame below the beltline are not in close proximity to the belowbelt glass runs and are therefore unavailable for providing reinforcing support to the elastic member or guide liner to stabilize or counter forces exerted by the window along its edges when it is being raised or lowered as is the case with the window sealing elements. Accordingly, conventional belowbelt guide means generally include a rigid retainer having a U-shaped cross section into which the guide liner is received. The rigid retainer is generally made of a tough, high modulus material such as steel and is rigidly fixed to the frame e.g. by welding or mechanical fasteners. The rigid retainer supports the guide liner and acts to stabilize forces exerted onto the belowbelt glass run by the window especially when it is being raised or lowered. In Fig. 3 of US-A-4,098,134 and in US-A-4969293 a typical prior art belowbelt glass run comprising an underlying steel support member having a U-shaped channel and an elastomeric liner received within the U-shaped channel is shown. Conventional belowbelt glass runs comprising a support member and separate guide liner are generally adequate for holding the glass on track with a smooth, consistent motion as the window is being raised or lowered in the door. Automobile and automotive component manufacturers are, however, continually endeavoring to provide high quality components which meet or exceed consumer expectations while simultaneously reducing manufacturing and assembly costs. Accordingly, a belowbelt glass run design which is capable of smoothly guiding a window of a vehicle door and which incorporates a simpler design comprising fewer components, and so with low manufacturing and assembly costs, would be highly desirable. One aspect of this invention is a glass run guide for guiding the sliding edge of a slidable vehicle window pane at a position below the window opening of a vehicle body, comprising an elongate strip member having a base and opposed inboard and outboard side walls forming a U-section channel which receives the pane edge, each of the side walls contacting the pane by a flexible lip projecting from the side wall along its length, characterised in that the elongate strip member is a stiff polymeric member whose polymeric base and side walls have sufficient rigidity to define of themselves a stiff channel capable of retaining the pane edge and restraining it against movements transverse to the sliding direction. The guide may have longitudinally local securing locations or securing means, spaced along its length, for securing it to the vehicle body. The stiff channel can be made transversely substantially oversize for the window pane. The flexible lip on each of its side walls, preferably formed in one piece therewith of the same material, bears slidably and resiliently against the respective window pane surface for fine guiding of the sliding movement. The contact lip is preferably formed as a cantilever or "finger" portion, desirably having a arcuate cross-section which is convex where it contacts the window pane. Thus, each side wall may comprise, in one piece, a thick, stiff side wall portion to restrain the pane against undesired lateral or "skew" movements, and a thin, flexible contact lip portion for fine guiding of the sliding movement. A low-friction coating or flocking is preferred on the contact lip, and optionally elsewhere as well. The pane-receiving portion of the member may be of substantially uniform cross-section along its length. Since the polymeric member has sufficient rigidity to support its own shape and restrain the pane against undesired movements, it can be mounted in the vehicle body without the coextensive rigid support required in the prior art. The polymer member may be formed in one piece, or more preferably in two pieces which are subsequently joined along a longitudinal joint. Moulding is the preferred method. Fibre-reinforced plastic is the preferred material. Another aspect of the invention is an automobile door window assembly in which a window pane is slidable in a vehicle door window opening under of the control of a window regulator mechanism, and front and rear glass run guides as described above are mounted in the vehicle door to extending below the window opening in the sliding direction, to receive the front and rear pane edges and thereby guide and restrain the movement of the pane. Each guide member may be fixed to the door structure only at plural spaced longitudinally-localised portions thereof. Another general aspect of the invention is a moulding method in which inboard and outboard portions of the element are separately formed and then joined to one another to form the channel section. Other preferred and optional features are set out in the sub-claims. A simple and efficient one-piece glass run guide assembly for a slidable vehicle window can be provided. It does not require a separate support member around a channel liner. This reduces the number of components needed, thereby reducing the amount of time and effort required for installation and providing an effective lower cost alternative to conventional glass run assemblies having separate guide and retainer means. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side elevation view of a vehicle door having a slidable window, portions are broken away to show the guide members contained within the door well; Fig. 2 is a side elevation view of a guide member; Fig. 3 is a front elevation view of the guide member of Fig. 2; Fig. 4 is a transverse cross-sectional view of the guide member shown in Figs. 2 and 3; Fig. 5 is an elevation view of a molding apparatus for molding a guide member; Fig. 6 is an elevation view of the molding apparatus of Fig. 5 with the mold open and with the divider plate removed; Fig. 7 is an elevation view of the molding apparatus of Fig. 5 with the mold open and showing robotic means in phantom for applying adhesive and optional functional coating; and Fig. 8 is an elevation view of the molding apparatus of Fig. 5 showing the mold closed with the divider plate removed. There is shown in Fig. 1 a left front door 10 of an automobile provided with a slidable glass window 12. The window is capable of being raised or lowered by any of various door window regulator means (not shown) e.g. as well known in the art. The window opening is defined by an upper or header section 14 of the door frame, a pair of laterally spaced pillars 16 and 18, respectively known in the art as the A and B-pillars, and the upper edge of the sheet metal door panels, known in the art as the beltline 19. Above the beltline, the window is guided by sealing elements attached to the door frame along the periphery of the window opening, and retained or restrained from undesirable inboard, outboard, forward and backward movement by the header and pillar sections of the door frame. Below the beltline, the window is guided by a pair of parallel laterally spaced guide members 20 and 22. Because the guide means 20 and 22, particularly the forward guide means 20, are spaced away from the edges of the door frame, the door frame is generally not capable of serving as a retainer means for restraining the window against undesirable inboard, outboard, forward and backward movement of the window. Accordingly, the guide means 20 and 22 must serve the dual functions of providing a resilient, non-abrasive surface which smoothly guides the window along its edges during raising or lowering of the window, and of providing reinforcement or support to counter forces exerted from the edges of the sliding window to prevent undesirable movement thereof. Each guide means 20 and 22 comprises a one-piece component molded from a polymeric material. The guide means 20 and 22 are generally similar and will therefore be described with reference to the forward guide means 20, shown in Figs. 2-4; the details of the rearward guide means 22 being readily determinable and obvious from the description of the forward guide means 20. In Fig. 2, there is shown a side elevational view of forward guide means 20 as seen when facing the inboard side of the guide means. Current vehicle body designs generally include doors and door windows having a small amount of outward curvature, i.e. the exterior surfaces of the door and door window have a generally large radius curved surface about an axis generally parallel with the longitudinal axis of the vehicle. Accordingly, the guide means 20 is preferably a curved strip as shown in Fig. 3 to accommodate the curvature of the window 12. A transverse cross sectional view of the guide means 20 is shown in Fig. 4. The guide means generally has a substantially U-shaped overall transverse cross section including a base 24, an inboard leg 26 and an outboard leg 28. The inboard and outboard legs, 26 and 28 respectively, include projecting lip portions 30 and 32 which engage the interior and exterior surfaces respectively of window 12 to smoothly guide it during its upward or downward travel. In accordance with a preferred aspect herein, mounting means are integrally formed during the molding of the guide means. The mounting means preferably includes an integral clip 34 near the upper end of the guide means 20 and 22, and a fastening lug 36 near the bottom end of the guide means and having a central hole 38 for receiving a conventional fastener, such as a threaded bolt which can also, for example, pass through a corresponding hole in the door frame, to fasten the guide means to the door frame. The clip 34 can be adapted to be received in a slotted opening of the door frame, thus simplifying installation procedure so as to include, for example, the steps of sliding the clip through the slotted opening of the frame, and using a single bolt to rigidly secure the guide means 20 to the door frame. As will be readily appreciated by those of ordinary skill in the art, the disclosed cross-sectional shapes for the guide means and the mounting means for securing the guide means to the vehicle door can be readily modified, or adapted to be used in vehicle doors having a variety of different shapes and designs. In accordance with one preferred version the guide means 20 and 22 are each formed with separate inboard and outboard guide elements 40 and 42, respectively, which are subsequently fused or otherwise joined to one another to provide for a practical, cost effective means of mass production. Such guide means may be produced by a split mold process wherein the inboard and outboard guide elements 40 and 42 are simultaneously injection molded in a mold assembly having two mold cavities separated by a removable divider plate. The mold is opened after the two guide elements are formed and the divider plate is removed. After the divider plate has been removed, adhesives are applied to selected surfaces of one or both of the guide elements 40 and 42. With the adhesive having been applied to at least one of the guide elements, the mold is reclosed without the divider and the two guide elements are bonded to one another to form a one-piece guide member, such as 20 or 22, which is adapted to facilitate smooth movement of the glass window 12 as it is being raised or lowered and to provide rigid retaining means whereby forces exerted from the edges of the window are countered to inhibit or prevent undesirable inboard, outboard, forward or rearward movement of the window. The guide elements 40 and 42 are preferably formed with interlocking means, such as a tongue 43 and groove 44, which facilitate or enhance joining of the guide elements. Thus, while it is presently preferred that the guide elements be joined by a combination of adhesives and interlocking means, it is also possible to secure the guide elements together using adhesives alone or interlocking means alone. An embodiment of injection press molding apparatus suitable for forming glass run guide members as set out above is shown in Figs. 5 - 8. The mold generally comprises an upper die plate 45, a removable divider plate 46, and a lower die plate 48. The upper die plate and one side of the removable divider plate together define the mold cavity 50 for one of the guide elements 40 or 42, and the lower die plate and the other side of the removable divider plate together define the mold cavity 52 for the other guide element. With the mold closed as shown in Fig. 5, a suitable moldable thermoplastic or thermosetting polymeric composition, preferably containing fiber reinforcement, is substantially simultaneously injected into both of the mold cavities 50 and 52. Thermoplastic polymers are generally preferred because they have lower cycle times and are more easily compounded to consistently and repeatedly produce seal assemblies having any of a wide variety of desirable properties. After the inboard and outboard guide elements have been formed, the mold is opened and the divider plate 46 is removed as shown in Fig. 6. With the mold open, adhesive materials are then applied to selected surfaces of the inboard, outboard, or both guide elements, preferably by preprogrammed robotic means 54 as shown in Fig. 7. Additionally, functional coating, such as flocking adhesive or low friction coating, can be applied if desired, also preferably by preprogrammed robotic means 56. Thereafter, as shown in Fig. 8, the mold is again closed, without the divider between the inner and outer dies, to secure the guide elements 40 and 42 together. Optionally, heat can be applied to the mold to, for example, cure the adhesive if a heat curable adhesive is selected, or to fuse the elements together to form a one-piece guide means, such as 20 or 22. The mold is then opened and optionally flocking can be applied if desired. Alternatively, an optional low friction coating can be applied to selected surfaces such as the surfaces of the lip portions 30 and 32 which contact the surfaces of window 12. The completed guide means 20 or 22 is then removed from the mold and the process can then be repeated to produce additional guide means. Alternatively, the guide means can be formed in a mold assembly having a single mold cavity. However, due to the complicated geometry of the guide means, the aforementioned split mold process is preferred. An important characteristic is that the guide means be provided with a low friction, non-abrasive surface for engaging the interior and exterior surfaces of the window near the edges thereof to provide for smooth movement of the window along the guide during raising or lowering of the window, while simultaneously having sufficient strength and rigidity to counter the forces exerted by the edges of the window to prevent undesirable inboard, outboard, forward or rearward movement during normal operation of the window. Accordingly, the window guide means should be of a resilient polymeric material simultaneously possessing a low coefficient of friction with glass, and a relatively high modulus, flexural and tensile strength. Suitable thermoplastics include polypropylene, polyamide, polyester, polyurethane, polyacetal, polyethylene, polyvinyl chloride, acrylonitrile-butadiene-styrene, acrylic-styrene-acrylonitrile, fluoro polymers, and other typical thermoplastics or alloys thereof. Suitable thermosetting compositions include crosslinked polyurethane, high modulus elastomers, such as EPDM, and other suitable thermosets with plastic characteristics such as epoxies. The polymeric materials used to form the vehicle door window guide means may be compounded with additives e.g. as known in the art, including antioxidants, antimicrobials, lubricants, mold release agents, plasticizers, and the like, as desired.

Claims: A glass run guide for guiding the sliding edge of a slidable vehicle window pane at a position below the window opening of a vehicle body, comprising an elongate strip member (20,22) having a base (24) and opposed inboard and outboard side walls (26,28) forming a U-section channel which receives the pane edge, each of the side walls (26,28) contacting the pane by a flexible lip (30,32) projecting from the side wall along its length, characterised in that the elongate strip member (20) is a stiff polymeric member whose polymeric base and side walls (24,26,28) have sufficient rigidity to define of themselves a stiff channel capable of retaining the pane edge and restraining it against movements transverse to the sliding direction. A glass run guide according to claim 1 comprising two moulded guide elements (40,42) joined to one another along a longitudinal joint, and respectively providing the inboard and outboard side walls (26,28) of the U-section channel. A glass run guide according to claim 2 in which the longitudinal joint of the guide elements (40,42) is secured by adhesive. A glass run guide according to claim 2 or claim 3 in which the guide elements (40,42) have integrally moulded parts (43,44) which interlock at the longitudinal joint. A glass run guide according to claim 4 in which one of the guide elements (40) has a longitudinal groove (44) which fits an interlocking tongue (43) on the other guide element (42). A glass run guide according to any one of the preceding claims in which the flexible lips (30,32) are in one piece with their respective side walls (26,28), of the same material. A glass run guide according to any one of the preceding claims in which the flexible lips (30,32) have a low-friction coating or flocking to contact the window pane. A glass run guide according to any one of the preceding claims in which the elongate strip member (20,22) is of fibre-reinforced thermoplastic material. A glass run guide according to claim 8 in which the fibre reinforcement is glass fibre and the thermoplastic material is selected from EPDM, polypropylene, polyamide, polyester, polyurethane, polyacetal, polyethylene, polyvinyl chloride, acrylonitrile-butadiene-styrene, acrylic-styrene-acrylonitrile, fluoro polymers and alloys thereof. A glass run guide according to any one of claims 1 to 7 in which the elongate strip member (20,22) is of fibre-reinforced thermosetting material. A glass run guide according to claim 10 in which the thermosetting material is selected from unsaturated polyesters, crosslinked polyurethanes, high modulus elastomers and epoxy resins. A glass run guide according to any one of the preceding claims comprising integrally-formed securing locations or securing means (34,36) spaced along its length, for securing the guide to the vehicle body. A glass run guide according to claim 12 in which the securing means comprises a clip (34). A glass run guide according to claim 12 or claim 13 in which the securing means comprises a fastening lug (36), moulded integrally with the strip member (20,22) and having a hole (38) through which a fastener can be passed. An automobile window assembly in which a window pane (12) is slidable in a window opening of a vehicle door (10) under the control of a window regulator mechanism, and front and rear glass run guides (20,22) as defined in any one of claims 1 to 14 are mounted in the vehicle door (10) extending below the window opening in the sliding direction of the window pane (12), to receive front and rear edges of the window pane (12) respectively and thereby guide and restrain sliding movements of the window pane. An automobile window assembly according to claim 15 in which each glass run guide (20,22) is mounted in the vehicle door (10) by fixing at plural spaced longitudinally-localised portions thereof. A method of making a glass run guide as defined in claim 2 or any claim dependent thereon, comprising separately moulding the inboard and outboard guide elements (40,42) and joining them by a longitudinal joint to form the U-section channel.

Inventors: DUPUY RONALD E, DUPUY, RONALD E.
Applicants: GENCORP INC, GENCORP INC.
Application year: 1994
Main classification: B60J10
IPC codes: B60J10, E05F11